Method of forming a seal

Details Method of forming a seal Method of forming a seal

1999-10-20

2002-04-09

Williams, Hezron (Department: 2856)

Measuring and testing

Vibration

By mechanical waves

C073S600000, C073S602000, C082S001110

Reexamination Certificate

active

06367331

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to assuring the thickness of a sealant. More specifically, the invention relates to using ultrasonic techniques to determine the thickness of a sealant.
BACKGROUND OF THE INVENTION
Submarine fiber optic communication systems carry a large majority of the information that is transmitted between the world's continents. These fiber optic communication systems remain in-place on the bottom of the ocean under thousands of feet, and even miles, of water for years at a time. Due to the difficulties encountered when having to repair, replace, or generally service these systems, it is desirable that these systems be highly reliable.
Submarine fiber optic communication systems typically include repeaters that appear at regular intervals along the spans of undersea cables to amplify the optical signals traversing the constituent fibers. Other assemblies that may be found along a submarine communication system including branching units, which allow multiple cable stations to be served from a single cable. To protect the sensitive components and/or connections that are housed within these submerged assemblies, a rugged hermetically sealed structure must be employed.
FIG. 1
illustrates a cross-sectional view of a known submarine fiber optic communication device
10
. Communication device
10
can be surrounded by seawater
12
, and can be connected to other submarine fiber optic transmission devices (not shown) or to terminal units (not shown). Device
10
can be formed as a cylindrical container
14
. Once the internal optical components (not shown) are installed within cylinder
14
, an end cover
16
can be attached onto each of its longitudinal ends. Each transmission device end cover
16
can define a seal well
80
having an aperture that penetrates cover
16
. Each seal well
80
can surround a seal assembly
100
. An external communications cable
20
can connect to each seal assembly
100
.
FIG. 2
provides a cross-sectional view of seal assembly
100
, within which external communications cable
20
can be connected to internal communications cable
36
. External communications cable
20
can contain an external secondary jacket
22
which can surround an external fiber shield
24
through which optical fibers
38
can pass. External guide tube
24
can be connected to tube
28
, which can be connected to internal guide tube
34
. Thus, a continual chamber
40
can be formed through which optical fibers
38
can pass from the outside to the inside of device
10
(not shown in FIG.
2
). Internal guide tube
34
can be surrounded by internal secondary jacket
32
.
Seal assembly
100
can have a circular cross-section, and can include an elongated annular plunger
110
having plunger front face
112
, plunger rear face
114
, and plunger circumferential face
116
. Seal assembly
100
can also include an elongated annular disk
120
having disk front face
122
, disk rear face
124
, and disk circumferential face
126
. Although plunger
110
and disk
120
can be coaxial, plunger
110
can have a larger outer diameter than disk
120
.
Sealant
130
can be attached to, and formed simultaneously with, internal secondary jacket
34
and external secondary jacket
22
. Sealant
130
can also be molded over disk front face
122
and disk rear face
124
of disk
120
, as well as around circumference
126
of disk
120
, to form encased disk
140
. Encased disk
140
can be coaxial with disk
120
, and can define sealant front face
142
, sealant rear face
144
, and sealant circumferential face
146
. Plunger front face
112
can be attached to sealant rear face
144
, such that plunger
110
and encased disk
140
are coaxial. A sufficient amount of sealant
130
can be removed from the circumference of encased disk
140
so that sealant circumferential face is flush with plunger circumferential face.
Plunger
110
and disk
120
can be constructed of any material that can withstand the loads anticipated to be imparted thereon. Sealant
130
can be constructed of polyethylene. Alternatively, sealant
130
can be constructed of any dielectric material that can sufficiently deform under preselected pressures to form a seawater seal.
FIG. 3
shows a cross-sectional view of seal assembly
100
installed in seal well
80
. Seal assembly
100
can be installed in seal well
80
with rear face
114
of plunger
110
facing seaward. Seal well
80
can define well base
82
across its annular bottom, and well surface
84
along its inner circumference. Sealant front face
142
can contact well base
82
to form primary seal
150
. Sealant circumferential face
146
can contact well surface
84
to form secondary seal
160
.
Primary seal
150
and secondary seal
160
can be formed by applying pressure to sealant
130
. Although this pressure can be supplied by the hydrostatic pressure of seawater
12
bearing against the rear face of plunger
110
, it can be desirable to create at least primary seal
150
during the manufacture of device
10
. The load necessary to establish at least primary seal
150
can be provided by the force of spring
170
bearing upon plunger rear face
114
. Spring
170
can be contained in seal well
80
by retaining ring
174
, which can ride in a retaining ring groove
86
that is cut in seal well
80
. The pressure of spring
170
can create an axial force against plunger rear face
114
. From plunger
110
, this force can be transferred onto sealant rear face
144
, through sealant
130
and disk
120
and sealant
130
again, through sealant front face
142
, and against well base
82
. By bearing against well base
82
, the sealant
130
of sealant front face
142
can slowly deform plastically to create initial primary seal
150
. The force through sealant
130
can also cause sealant
130
to slowly deform to create initial secondary seal
160
between sealant circumferential face
146
and well surface
84
. The force through sealant
130
can also cause any residual sealant
130
to flow into device
10
.
When device
10
is lowered a sufficient depth into the sea, the hydrostatic pressure of seawater
12
can create sufficient additional force against plunger rear face
114
, to again cause sealant
130
to plastically flow and deform. The force through sealant
130
can create, maintain, or enhance primary seal
150
and/or secondary seal
160
.
The dimensions of the components of sealwell
80
and seal assembly
100
can be designed and specified to be compatible with the expected dimensions of communications cables
20
and
36
, and the expected depth of operation of submarine fiber optic transmission device
10
. However, because of the need to form highly reliable seals, it can be important to manufacture each of the components of seal well
80
and seal assembly
100
to a relatively high degree of dimensional accuracy. This importance can include the accuracy of the dimensions of encased disk
140
. Notably, the portion of sealant
130
including and beneath sealant front face
142
can be removed to arrive at a reduced and desired sealant thickness between sealant front face
142
and disk front face
122
. Likewise, the portion of sealant
130
including and beneath sealant front face
142
can be removed to arrive at a reduced and desired length for seal assembly
100
.
FIG. 4
provides a cross-sectional view of seal assembly
100
. Referring to
FIG. 4
, the distance from plunger rear face
114
to initial sealant front face
142
′ is illustrated as dimension A′. Likewise, the distance from plunger rear face
114
to reduced sealant front face
142
″ is illustrated as dimension A″. The distance from disk front face
122
to initial sealant front face
142
′ is illustrated as dimension B′. Likewise, the distance from disk front face
122
to reduced sealant front face
142
″ is illustrated as dimension B″. Note that initial sealant front face
142
′ and dimensions A″ and B″ are potential positions and dimensions of sealant

Affiliated with

Also associated with

Rating

Method of forming a seal does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of forming a seal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of forming a seal will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2925169